Front loading refuse vehicle are used by contractors who employ a number of refuse receptacles, which are placed at various work sites where refuse is collected in them.
At regular intervals the vehicle with a container body and hoist will visit the site, and engage and lift the receptacle up over the cab of the vehilce. The receptacle in then inverted over the container body of the vehicle and refuse is dumped into the body through a trap door in the top of the body.
The receptacle is then replaced on the ground. Various different mechanisms have been proposed for lifting and tipping the refuse receptacles. Almost all of them employ two arms which can be extended forwardly of the vehicle. The two arms are adapted to be introduced into two sleeves, one on either side of the receptacle. In this way, the receptacle can be raised and tipped by the lifting mechanism or hoist.
Various different problems arise in the designing of such a mechanism and indeed the entire refuse vehicle.
For any given vehicle chassis, the weight of the lifting mechanism or hoist, is a factor in the pay load which the vehicle can carry. The heavier the hoist, the less the pay load.
Some hoisting mechanisms are more difficult to operate than others, and some hoisting mechanisms are more easily damaged than others.
In addition, the hoists are operated by hydraulic cylinders. The design of the hoist, as well as its weight, may be a factor in determining the size of the hydraulic cylinders required for its operation. Clearly, a lighter hoist, and a more efficiently designed hoist, will make more effective use of energy, thereby reducing fuel consumption, and speeding up the operation. One type of hoisting mechanism involves the use of two rails or ramps permanently attached to the front of the vehicle and curving rearwardly over the cab. Two arms are provided, which can be extended forwardly to engage sleeves on either side of the refuse receptacle. In this type of hoist, the two arms are mounted on rollers which roll on the rail, and thus follow a pre-determined fixed track from the front of the vehicle upwardly and over the cab, towards the trap door in the vehicle body. This system permits the design of the hoisting linkage to the substantially simpler, and also it can be fabricated out of lighter gauge steel.
One particular system of this type however uses the trap door on top of the vehicle body as part of the hoisting linkage. This system involves a penalty in the loss of mechanical efficiency, and the entire linkege extends up to a considerable height in order to rotate and dump the actual receptacle.
Accordingly, while this system has achieved considerable popularity, it fails to take full advantage of the principals on which it is based.